Two types of biomedical electrodes are used primarily in hospitals for EKG work. Both include a conductive backing laminated to a flexible electrically conductive gel matrix that is applied to the skin of a patient. In one type, a male snap connector is fastened to the backing. During use, a female snap connector at one end of a lead wire is snapped onto the male connector to make electrical contact with the electrode. The other type of electrode has no snap connector and is therefore substantially less expensive. Instead, it has a lateral extension or tab on one side or at the center to which an alligator clip can be fastened as described in U.S. Pat. Nos. 4,674,512 and 4,798,208. The problem with the second type, which will be referred to for convenience as a "tab" electrode, is that it cannot be readily connected to a female snap connector of the type in widespread use for making contact with the snap-type electrodes. As a result, many hospitals and clinics cannot benefit from the cost savings provided by the tab electrodes. Moreover, alligator clip connectors sometimes slip off and are therefore not entirely satisfactory under certain circumstances.
In view of these and other deficiencies of the prior art, it is a general objective of the invention to provide an improved means for using a female snap connector to make electrical contact with a tab electrode that has no male counterpart to the female snap connector, i.e. no male stud. Another object is to enable a lead wire provided with the female snap connector to be used with tab-type electrodes. A further object is to provide a means that allows existing snap-type leads to be reliably connected to a tab electrode or, on other occasions, to be connected in the usual way to a snap-type electrode so that it is not necessary to change leads when making a change from a snap electrode to a tab electrode.
These and other more detailed and specific objectives of the invention will be better understood by reference to the following detailed description an figures which illustrate by way of example but a few of the various forms of the invention within the scope of the appended claims